STOCKS FALL: Here's what you need to know

Wikimedia Stocks ended slightly lower after trading in a narrow range for much of the session on Monday, ahead of the Fed's interest rate announcement on Thursday. Trading volume was lighter than usual.

First, the scoreboard:

Dow: 16,370.96, -62.13, (-0.38%)

S&P 500: 1,953.03, -8.02, (-0.41%)

Nasdaq: 4,805.76, -16.58, (-0.34%)

And now, the top stories on Monday:

Barron's published a damning cover story on Alibaba over the weekend that the company, of course, took issue with. The magazine cast doubt on the veracity of Alibaba's financial numbers, and said its stock is likely to fall about 50% amid concerns about its valuation. It dropped 3% to as low as $61.48 in trading on Monday. Alibaba replied with a point-by-point take down of the article in a letter, calling it factually inaccurate, and standing by its financials. And, SunTrust analyst Bob Peck - who rates the stock a "Buy" with a price target of $100 - said some things in Barron's story may have been blown out of proportion.

OPEC says cheaper oil is hammering US shale producers. "In North America, there are signs that US production has started to respond to reduced investment and activity," the 12-member oil cartel wrote in its latest monthly market outlook. It's a small victory for OPEC, which had held sway over oil prices before the price collapse, and has pegged output above its targets to fight for market share from shale producers. It reduced its estimate for US production in 2015 by 100,000 barrels per day to 13.75 million.

Inflation expectations are falling. The New York Fed's latest Survey of Consumer Expectations showed this, and it is crucial at a time when the Fed could hold rates near zero on concern that inflation prospects are soft. However, last month, Fed vice chairman Stanley Fischer noted in a speech that longer-term inflation appears to be stable.

There's no shortage of forecasts from Wall Street for what the Fed announces on Thursday. BlackRock's Rick Rieder says a strong labor market is one reason why the Fed has, in fact, missed a window of opportunity to raise rates. Strategists at Morgan Stanley say their base case scenario is a " hawkish pass", meaning the Fed skips a hike because of the recent tightening of financial conditions, but leaves October or December on the table. And for Citi, the most important take away for consumers would be the Fed's message about the economy.

Apple says preorders of the iPhone 6S were " very strong" on the first weekend. The company said sales will likely surpass last year's opening weekend for the iPhone 6, when 10 million devices were sold. However, ace Apple analyst Gene Munster said the figures were driven more by production, making it difficult to glean actual demand.